First, make sure you can make the shot without the pacer ball. Set the two ball combination with a ball on the spot and another one frozen to it so their centers are lined up towards the long rail half of the corner pocket. This should also set their tangent line up to the other corner. Find a cue ball position where you can consistently make the shot. I like it just under 1-1/2 diamonds from the long rail, just behind the headstring. I aim for a half ball hit on the first object ball in the combo with lots of left and a half tip of follow.